1. Field of the Invention
The present invention relates to bead applicating devices for applying a bead or caulking to a workpiece. More specifically, the present invention relates to a bead applicating machine for applying a bead to a deformed workpiece.
2. Description of the Prior Art
Many devices have been developed for applying a bead, caulking material or the like to a workpiece. For example, U.S. Pat. No. 5,344,668 to Rempe et al. discloses a nozzle for applying a fluid material to a work product. The nozzle is controlled by a roller which is adapted to engage the workpiece to guide the nozzle.
U.S. Pat. Nos. 5,415,693 and 5,437,727 both to Yoneda et al. disclose an apparatus for dispensing fluid material onto a substrate according to a predetermined pattern. The applicator includes a nozzle positioned above the substrate mounted on an X-Y positioning table. An optical sensor is positioned adjacent the nozzle to control the process.
U.S. Pat. No. 4,661,368 to Rohde et al. discloses a dispensing nozzle for applying flowable material to a workpiece such as a circuit board. The apparatus provides that the nozzle tip is engaged with the workpiece with the reactive force between the workpiece and the nozzle being sensed to set the appropriate spacing between the nozzle tip and the workpiece.
U.S. Pat. No. 4,584,964 to Engel discloses a programmable machine for depositing viscous material onto a workpiece according to a predetermined pattern. The machine attaches a dispensing nozzle on an X-Y positioning carriage above the workpiece with the carriage being controlled to follow a preprogrammed pattern.
U.S. Pat. No. 4,546,723 to Leopold et al. discloses an apparatus for applying a sealant to insulating glass panel spacer frames. Segments of the frame are advanced longitudinally past a sealant applying station where the sealant is applied appropriately in response to photosensors which determine the presence of the frame.
U.S. Pat. No. 4,085,238 to Chenel et al. discloses an apparatus for applying a plastic film to the edge of a glass workpiece. An extrusion nozzle is positioned above the glass workpiece which is fed past the nozzle by a conveyor. A photoelectric cell senses the edge of the glass workpiece to automate and control the process.
An apparatus in which the dispensing nozzle is positioned on an X-Y-Z positioning carriage to follow a preprogrammed pattern, such as described in some of the prior art patents discussed above, represents one of the most common types of bead applicating devices. Problems can arise in these systems if the workpiece does not conform precisely to the idealized workpiece intended when developing the predetermined pattern for the carriage. In the application of bead or caulking to a window frame, a bent or distorted frame member will often result in a misapplied bead.
It is an object of the present invention to overcome the drawbacks of the above-described prior art. It is a further object of the present invention to provide a nozzle apparatus which can follow a deformed or distorted workpiece. It is a further object of the present invention to provide a nozzle apparatus which can be retrofitted to existing bead applicating devices. It is a further object of the present invention to provide a bead applicating machine which is easily constructed and simple to use. It is a further object of the present invention to provide a method of applying a bead to a workpiece which accommodates distortions in the workpiece.